Eye Surgery System

ABSTRACT

An eye surgery system  1  comprises microscopy optics  3  and an OCT device  5  to generate a light-optical image and an OCT image of an eye fundus  11,  a controller  29  and a visualization system  13, 41, 83.  The controller comprises a data interface  97  for receiving a preoperative OCT image and may control the visualization system to display a representation of the received preoperative OCT image. The controller may control the OCT device  5  to record an intraoperative OCT image and may control the visualization system to display a representation of the recorded intraoperative OCT image. The controller may adjust a magnification of the representation of the intraoperative OCT image and/or a magnification of the representation of the preoperative OCT image so that the magnifications of the representation of the intraoperative OCT image and the magnification of the representation of the preoperative OCT image are equal.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims priority of Patent Application No. 102014 010 350.1, filed Jul. 10, 2014 in Germany, the entire contents ofwhich are incorporated by reference herein.

FIELD

The invention relates to eye surgery systems comprising microscopyoptics for generating a light-optical image of an eye fundus and an OCTdevice for generating an OCT image of the eye fundus.

BACKGROUND

Such eye surgery systems may be used to perform surgical interventionsat the retina of an eye of a patient. A surgeon may continuously observethe light-optical image of the eye fundus while performing manipulationsat the retina of the eye using surgical tools. Further, the surgeon mayverify the result of the manipulations using intraoperative OCT imagesgenerated during the intervention. For this, it is desirable to comparea current result of the intervention to a preoperative OCT imageobtained prior to the intervention to be able to assess a success of theintervention better and to plan further necessary measures. Therefore,it is further desirable to observe and compare the light-optical imagegenerated during the intervention, the OCT image generated during theintervention and the OCT image generated prior to the interventionsimultaneously or at least consecutively at short temporal distances.

SUMMARY

It is an objective of the present invention to suggest an eye surgerysystem of the previously mentioned kind allowing to observeintraoperative OCT images, i.e. OCT images obtained during theintervention, preoperative OCT images, i.e. OCT images obtained beforethe intervention, and intraoperative light-optical images, i.e.light-optical images obtained before the intervention, of an eye fundusduring a surgical intervention.

Embodiments of the invention provide an eye surgery system comprising anoptical system, a controller and a visualization system. The opticalsystem comprises microscopy optics and an OCT device. The microscopyoptics are configured to generate a light-optical image of an eyefundus. The OCT device is configured to scan the eye fundus using an OCTmeasurement beam and to generate an OCT image of the eye fundus.

The microscopy optics may comprise an objective lens and an auxiliarylens which are disposed close to the eye and which support imaging ofthe eye fundus. This auxiliary lens may be disposed at a distance fromthe eye, be mounted separately and generate an image of the eye fundusas an intermediate image which, in turn, is further imaged by theobjective lens. Such an auxiliary lens may also be referred to as anophthalmoscopy magnifying glass. The auxiliary lens may also be indirect contact with the cornea of the eye but does not generate anintermediate image of the eye fundus so that the auxiliary lens and theobjective lens together will generate the image of the eye fundus. Suchan auxiliary lens may also be referred to as a contact glass. Herein,each of the objective lens and the auxiliary lens may consist of one orplural lens elements and, in particular, may also comprise mirrors.Then, an ocular or a pair of oculars may be disposed in the beam pathbehind the objective lens, wherein the surgeon may look into the ocularor the pair of oculars using one eye or both his eyes in order toobserve the light-optical image of the eye fundus. Furthermore, a cameramay be disposed in the beam path behind the objective lens, and detectan image of the eye fundus. Then, the image may be displayed by avisualization system so that the surgeon may observe the image.

The OCT device comprises an interferometer having a reference path and ameasurement path where the eye fundus is disposed so that an OCTmeasurement beam generated by the OCT device is incident onto the eyefundus and an interference of measurement light reflected orbackscattered from the eye fundus with measurement light having passedthe reference path is detected. Furthermore, the OCT device may comprisedeflector elements for the OCT measurement beam to scan the OCTmeasurement beam across the eye fundus and to generate the OCT image ofthe eye fundus thereby.

The OCT device and the microscopy optics may share same opticalcomponents. For example, the OCT measurement beam may traverse theauxiliary lens, such as an ophthalmology magnifying glass or a contactglass, or the objective lens of the microscopy optics.

According to exemplary embodiments, the microscopy optics comprise atleast one ocular for generating a representation the light-optical imageof the eye fundus and a display apparatus for displaying arepresentation of the OCT image generated by the OCT device, wherein thevisualization system further comprises optics configured to project therepresentation of the OCT image displayed by the display apparatus intoa beam path of the at least one ocular so that the representation of theOCT image and the representation of the light-optical image may beobserved in the at least one ocular. Herein, the visualization systemmay be configured so that the representation of the light-optical imageand the representation of the OCT image are displayed simultaneously andbe adjacent, e.g. next to each other. That is, an observer may observethe representation of the light-optical image and the representation ofthe OCT image while the representations are located adjacent to eachother. Furthermore, the light optical image and the OCT image may bedisplayed in superposition, i.e. representations of both images mayfully or partially overlap each other.

According to further embodiments, the microscopy optics comprise acamera configured to detect the light-optical image of the eye fundusand the visualization system comprises a display to display arepresentation of the detected light-optical image and a representationof the generated OCT image. Also herein, the representation of bothimages may be displayed by the display simultaneously and be adjacent toeach other, e.g. next to each other or spatially overlapping each other.

Furthermore, both images may be displayed simultaneously and beoverlapping or be displayed consecutively so that either therepresentation of the light-optical image or the representation of theOCT image may be observed at a single point in time.

According to further exemplary embodiments, the controller controls,e.g. invokes, the visualization system to display the representation ofthe OCT image. When the light-optical image is detected by a camera, thecontroller controls the visualization system to display therepresentation of the image.

According to exemplary embodiments, the controller comprises a datainterface to receive a preoperative OCT image. Then, the controller maycontrol the visualization system to display a representation of thereceived preoperative OCT image as well as the representation of theintraoperative OCT image. Also herein, representations of the receivedpreoperative OCT image and the intraoperative OCT image may be displayedsimultaneously or consecutively and be adjacent, e.g. next to each otheror overlapping each other.

According to exemplary embodiments herein, the controller is configuredto adjust a magnification of the representation of the intraoperativeOCT image and/or a magnification of the representation of thepreoperative OCT image. According to exemplary embodiments herein, thecontroller is further configured to display representations of theintraoperative OCT image and the preoperative OCT image at samemagnifications by the visualization system. This is especially favorablefor the surgeon as he may compare both representations of the OCT imagesto each other particularly well and may plan further steps based on thiscomparison.

According to exemplary embodiments, the controller is further configuredto adjust the magnifications of the representations so that, besides theintraoperative OCT image and the preoperative OCT image, also therepresentation of the intraoperative light-optical image is displayed atthe same magnification.

Two representations of images of the eye fundus may be regarded as tohave the same magnification if a distance between two structures of theeye fundus visible in both representations have the same distance in therepresentations of both images.

According to exemplary embodiments herein, the controller is furtherconfigured to adjust an orientation of the representation of theintraoperative OCT image and/or an orientation of the representation ofthe preoperative OCT image. According to further exemplary embodimentsherein, the controller is further configured to control thevisualization system to display the representation of the intraoperativeOCT image and the representation of the preoperative OCT image at sameorientations. In this case, the surgeon may compare these tworepresentations of images to each other particularly well and planfurther steps based on this comparison.

According to further embodiments, the controller is further configuredto adjust the orientations of the representations so that, besides theintraoperative OCT image and the preoperative OCT image, also therepresentation of the intraoperative light-optical image is displayed ata same orientation by the visualization system.

Two representations of images of the eye fundus may be regarded as tohave a same orientation if a straight line in the representation of afirst one of the two images and a straight line in the representation ofa second one of the two images have a same orientation, wherein each ofthe straight lines connects two structures of the eye fundus, whichstructures are visible in both representations. That is, the straightline connecting the two structures in the representation of the firstimage is orientated parallel to the straight line connecting therespective structures in the representation of the second image.

According to exemplary embodiments, the controller is configured toperform an image analysis of the preoperative OCT image and an imageanalysis of the intraoperative OCT image and to adjust, based on theseimage analyses, the magnification and/or the orientation of therepresentation of the intraoperative OCT image and/or the magnificationand/or the orientation of the representation of the preoperative OCTimage so that both representations of the OCT images are displayed atthe same magnification and orientation, respectively.

According to exemplary embodiments, if both OCT images are displayedsimultaneously in superposition or consecutively in a common region ofthe display, i.e. the representations of the images overlap each other,the controller may displace one of or both representations of the imagesby translation so that each structure of the eye fundus in bothrepresentations is displayed at a same location on the display.

The image analysis may recognize patterns in both OCT images andidentify differences between both images by comparing the patterns. Thecontroller may change the orientation of the representation of theimages or displace them relative to each other on the display based onthese differences.

According to further exemplary embodiments, the controller may obtaindifferences of the magnifications of the representation of thepreoperative OCT image and the representation of the intraoperative OCTimage by detecting at least one optical parameter of the recorderapparatus. Based on the detected at least one optical parameter, thecontroller may adjust the magnification of the representation of thepreoperative OCT image and/or the magnification of the representation ofthe intraoperative OCT image so that the magnifications are equal.Herein, the magnification of the preoperative OCT image may bepredetermined and, for example, determined by a diagnostics systemconfigured to record the preoperative OCT image. Herein, thepreoperative OCT image received via the data interface may always havethe same predetermined magnification or different magnifications, therespective values of which may then be transmitted to the controller bythe data interface together with the preoperative OCT images so that thevalue of the magnification of the received preoperative OCT image may beavailable to the controller. The controller may compare the value withthe magnification of the intraoperative OCT image, wherein themagnification of the intraoperative OCT image may be deduced from thedetected at least one optical parameter of the recorder apparatus.

The at least one optical parameter of the recorder apparatus mayrepresent a focal length of an objective lens of the optical systemand/or a focal length of an auxiliary lens of the optical system such asan ophthalmoscopy magnifying glass or a contact glass. The at least oneoptical parameter may further represent a magnification of a zoom systemdisposed in the beam path of the microscopy optics.

The focal lengths of the objective lens or the zoom system may bepredetermined, always be the same or be changeable. If the focal lengthsare changeable, the recorder apparatus may comprise sensors configuredto detect the focal lengths based on, for example, distances betweenindividual lens elements of the objective lens and the zoom system,respectively. Furthermore, the focal lengths of the objective lens orthe zoom system may be adjusted by actuators controlled by thecontroller so that respective focal lengths and parameters representingthese focal lengths are available to the controller.

According to exemplary embodiments, plural auxiliary lenses, such asophthalmoscopy magnifying glasses or contact glasses, having differentfocal lengths may be provided and individually selected to be disposedin the beam path of the optical system. In order to obtain the focallengths of the auxiliary lens currently in use, the controller maycomprise a user interface configured to receive data from a user, thedata providing for identification of the auxiliary lens disposed in thebeam path of the optical system. Alternatively or in addition, thecontroller may be configured to determine the auxiliary lens disposed inthe beam path of the optical system. This determination may be performedaccording to various kinds. For example, the controller may control theOCT device to perform measurements of distances between surfaces of lenselements of the auxiliary lens and identify the auxiliary lens in usebased on the measured distances. Furthermore, the different auxiliarylenses may have different marks on its lens carriers, the marks beingvisible in the light-optical image generated by the microscopy optics.By detecting and analyzing this image, the controller may identify theauxiliary lens in use based on the detected marks. Furthermore, thedifferent auxiliary lenses may have different electrical or mechanicalidentifiers readable by suitable electrical or mechanical contacts, thecontacts in turn being readable at a mount of the auxiliary lens in thebeam path.

BRIEF DESCRIPTION OF THE DRAWINGS

The forgoing as well as other advantageous features of the disclosurewill be more apparent from the following detailed description ofexemplary embodiments with reference to the accompanying drawings. It isnoted that not all possible embodiments necessarily exhibit each andevery, or any, of the advantages identified herein.

Hereinafter, embodiments of the invention are illustrates with referenceto Figures of which:

FIG. 1 shows a schematic illustration of an eye surgery system;

FIG. 2 shows a schematic illustration of a diagnostics system which maybe part of the eye surgery system of FIG. 1;

FIG. 3 shows a schematic illustration of a display of a visualizationsystem of the eye surgery system of FIG. 1;

FIG. 4 shows a schematic top view onto an ophthalmoscopy magnifyingglass and its mount; and

FIG. 5 shows a schematic illustration of a portion of another eyesurgery system.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the exemplary embodiments described below, components that are alikein function and structure are designated as far as possible by alikereference numerals. Therefore, to understand the features of theindividual components of a specific embodiment, the descriptions ofother embodiments and of the summary of the disclosure should bereferred to.

FIG. 1 is a schematic illustration of an eye surgery system 1. The eyesurgery system 1 comprises microscopy optics 3 configured to generatelight-optical images of an eye fundus 11 of an eye 8. The fundus 11 isimaged by the microscopy optics 3 of the illustrated exemplaryembodiment by a pair of oculars 13 on the one hand, into which a surgeonmay look with both his eyes, and on the other hand by a camera 15 whichmay record images of the fundus 11 and generate data representing theimages.

For this, the microscopy optics 3 comprise an auxiliary lens 9implemented as an ophthalmoscopy magnifying glass and generating anintermediate image of the fundus 11 in a plane 10. The microscopy optics3 further comprise an objective lens 17 which may consist of one orplural lens elements and, in particular, may image the intermediateimage formed in the plane 10 to infinity as shown in the illustratedexample. In the beam path behind the objective lens 17, each of twopartial beam bundles 19 passes a zoom lens assembly 21 capable ofchanging an imaging scale of the optics. For this, each of both zoomlens assemblies 21 may comprise at least two lens groups 22 and 23 whichare displaceable relative to each other in direction of the partial beambundle 19 as indicated by an arrow 24 in FIG. 1. The displacement of thelens groups 22 and 23 relative to each other is controlled by anactuator 25 which, in turn, is controlled by a controller 29 via acontrol wire 27 in order to adjust the imaging scale of the microscopyoptics 3.

Behind the zoom lens assemblies 21, each of the partial beam bundles 19enters one of the oculars 13. From the partial beam bundle 19 located onthe right side in FIG. 1, a portion of the light of the partial beambundle 19 is deflected by a partially transparent mirror 31 and directedonto the camera 15 by camera adapter optics 33 so that the camera 15 maydetect the image of the field of view of the object region where the eyefundus 11 is located. The data generated by the camera 15 aretransmitted to the controller 29 via a data wire 35.

The microscopy optics 3 further comprise two electronic image displays41 fed with image data from the controller 29 via the data wire 43.Representations of the images displayed by the image displays 41 areeach projected into the beam path towards the oculars 13 by projectionoptics 45 and a partially transparent mirror 47 disposed in the partialbeam bundle 19 so that the surgeon looking into the oculars 13 mayperceive the representations of the images displayed by the imagedisplays 41 in superposition with the light-optical image of the fieldof view of the object region 11.

The eye surgery system 1 further comprises an OCT device 5 forperforming OCT measurements. The OCT device 5 comprises an OCT assembly4 having a suitable light source of short coherence and aninterferometer, both not illustrated in FIG. 1. OCT measurement light isemitted from the OCT assembly 4 via a light guide fiber 51 so that theOCT measurement light may be incident onto an object to be measured,such as the eye fundus, and measurement light returning from the objectmay reenter the fiber so that the OCT assembly 4 may examine thisreturned measurement light and output data representing the measurement.In particular, the OCT assembly 4 may perform a depth scan also referredto as A-scan, the data of which represent intensities of backscatteredmeasurement light in dependence of the depth. The OCT assembly 4 iscontrolled by the controller 29 via a control and date wire 53. Thecontroller 29 also receives the measurement data generated by the OCTdevice 5 via this wire 53. The OCT device 5 further comprises collimatoroptics 59 which collimate OCT measurement light 57 emitted from an end55 of the fiber 51 to a measurement light beam 58. The measurement lightbeam 58 is deflected at two deflection mirrors 61 and 63, passesprojection optics 65, is incident onto a mirror 69 and is directed ontothe fundus 11 by the mirror 69 through the objective lens 17 and theauxiliary lens 9. A portion of the OCT measurement light isbackscattered at the fundus 11 so that the backscattered measurementlight passes the reverse path through the auxiliary lens 9 and theobjective lens 17, the projection optics 65 and the collimator optics 59so that at least a portion of this light is coupled into the fiber 51and returns to the OCT assembly 4 where it is examined using theinterferometer.

The mirrors 61 and 63 are pivotable in order to deflect the OCTmeasurement beam so that, by adjusting the pivot positions of themirrors 61 and 63, the OCT measurement beam 58 may be incident ontoselectable locations of the fundus 11. Pivotability of the mirrors 61and 63 is indicated by arrows 71 in FIG. 1. The pivot positions of themirrors 61 and 63 are adjusted by actuators 73 controlled by thecontroller 29 via control wires 75. By controlling the actuators 73, thecontroller 29 may scan the fundus 11 using the OCT measurement beam andmay generate an intraoperative OCT image of the fundus 11.

The controller 29 further comprises a user interface comprising a screen83 of a visualization system and a keyboard 84 and a mouse 85 as inputmedia. The visualization system also comprises the displays 41 forfeeding representations of images generated by the controller 29 intothe beam paths towards the oculars.

In the exemplary embodiment described herein, the eye surgery system isused to perform a microsurgical intervention at the fundus 11 using asurgical tool.

For this, the surgeon observes the representation of the light-opticalimage of the fundus and the representation of the intraoperative OCTimage through the ocular, the representation of the OCT image beingprojected via the display 41 and the optics 45. Alternatively, thesurgeon may observe representations of the light-optical image and theintraoperative OCT image on the screen 83. An example of suchrepresentations is schematically illustrated in FIG. 3. FIG. 3 shows thescreen 83 and images of the fundus displayed thereon. A representationof an image 91 shown on the left side in FIG. 3 is the representation ofthe light-optically image of the fundus 11 detected by the camera 15,whereas a representation of an image 93 shown on the right side of FIG.3 is the representation of the intraoperative OCT image of the fundus 11generated by the OCT device 5. Structures of the fundus 11 areschematically sketched by lines 95 in FIG. 3. Due to the differentrecording techniques used to obtain the images 91 and 93, the structures95 contained in the images are not identical, however they are similar.Based on a comparison of the representations of the images, the surgeonmay obtain valuable information.

The eye surgery system 1 is further configured to display arepresentation of the preoperative OCT image of the fundus by thevisualization system. FIG. 2 is a schematic illustration of adiagnostics system 101 for generating the preoperative OCT image. Thediagnostics system 101 comprises an OCT device 103 having an OCTassembly 104, which comprises a light source of short coherence and aninterferometer, scan mirrors 105 and optics 107 to generate ameasurement light beam 109. The patient rests, for example, his chinonto a rest element 111 so that the measurement light beam 109 may enterthe eye 8. The scan mirrors 105 are controlled so that a focus of themeasurement light beam 109 scans the fundus of the eye 8 of the patientto generate a preoperative OCT image of the fundus. The OCT image isoutput via a data interface 113.

The controller 29 comprises a data interface 97 to receive thepreoperative OCT image and may display a representation of it by thevisualization system. The representation of the preoperative OCT imagemay be displayed, for example as an image 99 (see FIG. 3) instead of theintraoperative OCT image 93, next to the representation of thelight-optical image 91 of the fundus 11. In particular, therepresentations of the preoperative OCT image 99 and the intraoperativeOCT image 93 may be displayed consecutively and alternately. Also, usingthe input medium such as the keyboard 84 and the mouse 85, the user mayselect which of the OCT images is/are to be displayed. Further,representations of the three images, i.e. the light-optical image 91,the intraoperative OCT image 93 and the preoperative OCT image 99, maybe displayed next to each other.

For each of the previously described ways of displaying therepresentations of the images 91, 93 and 99, it is desirable that theserepresentations are displayed at a same magnification, a sameorientation and are disposed relative to each other so thatcorresponding structures 95 of the fundus 11 are located atcorresponding locations in the representations of the images 91, 93 and99. For this, the controller 29 is configured to adjust themagnification of the representation of the intraoperative OCT image 93and/or the magnification of the representation of the preoperative OCTimage 99 via the visualization system. Furthermore, the controller maychange an orientation of the representation of the intraoperative OCTimage 93 relative to the orientation of the representation of thepreoperative OCT image 99. Also, the controller may displace the imagecontents of the intraoperative OCT image 93 and the preoperative OCTimage 99 by translation. To determine the correct values of themagnifications, the orientations and the translations of therepresentations of the images, the controller 29 may perform an imageanalysis of the images and identify structures 95 visible therein. Bycomparing the structures or suitable portions of the structures, thecontroller may determine values for adjusting the magnifications,orientations and translations. Suitable structures may be, for example,structures of the macula, structures of the visual nerve or bloodvessels.

The controller may further analyze the light-optical image 91 by imageanalysis and identify the structures 95 visible in the light-opticalimage. By another comparison between suitable structures contained inthe light-optical image 91 and one of or both of the OCT images 93 and99, the controller may adjust the magnification, the orientation and thetranslation of the representations of the OCT images 93 and 99 so thatcorresponding structures are displayed at the same locations in therepresentations of the three images. This is illustrated in FIG. 3:structures 95′ and 95″ on the fundus are shown in all three images asspots. The distances between representations of both structures 95′, 95″are equal in all three images on the screen 83 of the visualizationsystem. Furthermore, a straight line 96 connecting both structures 95′and 95″ with each other has the same orientation in the representationsof the three images 91, 93, 99 so that, for example, the straight line96 in the representation of the light-optical image 91 on the screen 83of the visualization system is parallel to the straight line 96 in therepresentation of the intraoperative image 93 and parallel to thecorresponding straight line in the representation of the preoperativeimage 99. Furthermore, the representation of the intraoperative image 93is displaced relative to the representation of the preoperative image 99so that the locations 95′ and 95″ in the representation of theintraoperative image 93 coincide with the locations 95′ and 95″ in therepresentation of the preoperative OCT image 99 on the screen 83 of thevisualization system, respectively.

FIG. 3 shows a mark 98 displayed by the controller 29 in therepresentation of the intraoperative OCT image 93. The representation ofthis mark is based on a diagnostics mark defined, for example, by adoctor in the preoperative image. For example, the doctor who assists ingenerating the preoperative OCT image and examines this image, definesthe diagnostics mark in the representation of the preoperative OCT imagein order to mark a specific location at the fundus for subsequenttreatment. Therefore, the diagnostics mark may support planning of thesurgical intervention. For example, this may be done in that the doctorobserves the representation of the preoperative OCT image on a screen ofa computer system and generates the mark using an input medium of thecomputer system. A suitable software of the computer system may storethe image coordinates of this diagnostics mark as data pertaining thepreoperative OCT image.

The controller 29 may obtain these image coordinates of the diagnosticsmark together with the preoperative OCT image via the data interface 97.Then, having adjusted the magnification, the orientation and thetranslation of the representation of the preoperative OCT image on thescreen 83 of the visualization system, the controller 29 may alsodisplay the mark 98 on the screen at a location in the representation ofthe intraoperative OCT image, the location corresponding to the locationof the diagnostics mark in the preoperative OCT image.

Instead or in addition to the determining of the requiredmagnifications, rotations and translations of the images based on animage analysis, it is also possible to determine the magnifications ofthe images by determining parameters of the optics in use. For example,the magnification of the diagnostics system 101 used during recording ofthe preoperative OCT image may be fixed, unchangeable and predetermined.The magnifications of the light-optical images visible via the oculars13 or the screen 83 may be determined from parameters of the microscopyoptics 3. These parameters may comprise adjustment values used to adjustthe zoom system 21 which is, in turn, controlled by the controller 29via the actuator 25; hence the adjustment values are available to thecontroller. In addition, the focal lengths of the objective lens 17 andthe auxiliary lens 9 are parameters influencing the magnification of thelight-optical image. If the objective lens 17 has a fixed focal length,the focal length is available to the controller 29. If this focal lengthis changeable, for example by two lens elements of the objective lens 17being displaceable relative to each other, the distances of the two lenselements from each other may be obtained by a sensor of the controller29. The controller may also control these distances by an actuatorsimilar to the actuator used to control the zoom system 21 so thatvalues of the selected adjustment are available to the controller 29.

The focal length of the auxiliary lens 9 may be predetermined. Often, itis desirable to use auxiliary lenses of different focal lengths. In thiscase, it is necessary that the type of the auxiliary lens 9 disposed inthe beam path is available to the controller 29. This can be achieved byproviding a user interface to the controller so that the user may enterdata, for example via the keyboard 84 or the mouse 85, identifying theauxiliary lens 9 currently in use. Furthermore, the controller maycontrol the OCT device 5 to measure distances between surfaces of lenselements of the auxiliary lens 9. Based on the measured distances, thecontroller 29 may determine the type of the auxiliary lens in use.Furthermore, the different auxiliary lenses may have differentidentifiers detectable by the eye surgery system 1. Three examples ofsuch identifiers are described hereinafter with reference to FIG. 4.

FIG. 4 schematically shows a top view onto an auxiliary lens, namely anophthalmology magnifying glass 9 disposed in the beam path of the eyesurgery system. The ophthalmology magnifying glass 9 comprises a lenselement 111 and a carrier 113 of the lens element 111. The carrier 113is mounted to a mount 115 holding the ophthalmology magnifying glass 9in the beam path of the eye surgery system 1. A first option of anidentifier identifying the ophthalmology magnifying glass 9 is anoptical mark 117 such as a bar code. The optical mark 117 is arranged onthe carrier 113 so that it is visible in the top view of FIG. 4.Accordingly, the optical mark 117 is also visible in the light-opticalimage recorded by the camera 15 and, hence, may be identified by thecontroller 29 through image analysis. For improving the result of suchan image analysis, it may be helpful to change the setting of themicroscopy optics so that the mark 117 is as sharply visible as possiblein the light-optical image.

A second option of an identifier is provided by an electrical storageelement 119 fixed to the carrier 113 and comprising data identifying theophthalmology magnifying glass 9. The content of the storage element 119may be read by the controller via a date wire 121 connected to thememory element 119 via a plug contact 122 when the ophthalmology glass 9is disposed at the mount 115.

A third option for an identifier is a mechanical identifier. Asillustrated, the mechanical identifier may be implemented by threeprojections 123 provided on the carrier 113, the three projections 123operating three out of four switches 125 provided at the mount 115. Afourth switch of the four switches 125 is not operated in theillustrated example as a projection 123 configured to operate the fourthswitch is not provided at the carrier 113. The configuration of theswitches 125 may be transmitted to the controller 29 via a date wire127.

Therefore, the controller 29 is capable of determining the magnificationof the recorded light-optical image based on parameters of themicroscopy optics 3. This is also possible for the magnification of therecorded intraoperative OCT image. In the illustrated example, the beampath of the OCT measurement light passes through the objective lens 17and the ophthalmology magnifying glass 9. Their focal lengths andparameters representing the focal lengths as described above may bedetermined. In addition, the magnification of the recorded OCT image isdetermined by parameters defined, for example, by the pivot positions ofthe mirrors 61 and 63 for scanning the fundus. Also, these parametersmay be available to or controlled by the controller 29. Therefore, alsothe magnification of the recorded intraoperative OCT image may bedetermined and compared to the magnification of the preoperative OCTimage to adjust the magnifications selected for the representation bythe visualization system so that the displayed OCT images have the samemagnifications.

FIG. 5 is a schematic illustration of a portion of an eye surgery system1 having a setup which is very similar to the setup of the eye surgerysystem shown in FIG. 1. In contrast to the eye surgery system shown inFIG. 1, the eye surgery system 1 of FIG. 5 does not use an ophthalmologymagnifying glass but a contact glass 9′ for imaging the fundus 11. Whilethe ophthalmology magnifying glass generates an intermediate image ofthe fundus to be further imaged by the objective lens, the contact glass9′ does not generate an intermediate image of the fundus 11 so that the(first) image of the fundus 11 is formed in the beam path behind theobjective lens 17.

While the disclosure has been described with respect to certainexemplary embodiments thereof, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, the exemplary embodiments of the disclosure set forthherein are intended to be illustrative and not limiting in any way.Various changes may be made without departing from the spirit and scopeof the present disclosure as defined in the following claims.

1.-19. (canceled)
 20. An eye surgery system comprising: an opticalsystem including microscopy optics and an OCT device, wherein themicroscopy optics are configured to generate a light-optical image of aneye fundus, and wherein the OCT device is configured to scan the eyefundus using an OCT measurement beam and to generate an OCT image of theeye fundus; a controller; and a visualization system; wherein thecontroller comprises a data interface to receive a preoperative OCTimage and is configured to control the visualization system to display arepresentation of the preoperative OCT image, wherein the controller isfurther configured to control the OCT device to record an intraoperativeOCT image and to control the visualization system to display arepresentation of the recorded intraoperative OCT image, wherein thecontroller is further configured to adjust at least one property of agroup of properties so that at least one condition of a first group ofconditions is fulfilled, the group of properties comprising amagnification of the representation of the intraoperative OCT image, amagnification of the representation of the preoperative OCT image, anorientation of the representation of the intraoperative OCT image and anorientation of the representation of the preoperative OCT image, thefirst group of conditions comprising: the magnification of therepresentation of the intraoperative OCT image and the magnification ofthe representation of the preoperative OCT image be equal; and theorientation of the representation of the intraoperative OCT image andthe orientation of the representation of the preoperative OCT image beequal.
 21. The eye surgery system according to claim 20, wherein thecontroller is further configured to control the visualization system sothat the representation of the preoperative OCT image and therepresentation of the intraoperative OCT image are displayedsimultaneously and are adjacent to each other.
 22. The eye surgerysystem according to claim 21, wherein the representation of thepreoperative OCT image and the representation of the intraoperative OCTimage are not overlapping each other.
 23. The eye surgery systemaccording to claim 21, wherein the representation of the preoperativeOCT image and the representation of the intraoperative OCT image areoverlapping each other.
 24. The eye surgery system according to claim20, wherein the controller is further configured to control thevisualization system so that the representation of the preoperative OCTimage and the representation of the intraoperative OCT image aredisplayed consecutively.
 25. The eye surgery system according to claim21, wherein the representation of the preoperative OCT image and therepresentation of the intraoperative OCT image are overlapping eachother.
 26. The eye surgery system according to claim 20, wherein thevisualization system comprises an ocular of the microscopy optics, adisplay and optics, wherein the ocular is configured to generate arepresentation of the light-optical image of the eye fundus, and whereinthe optics are configured to project at least one of the representationof the preoperative OCT image displayed by the display and therepresentation of the intraoperative OCT image displayed by the displayinto a beam path of the ocular.
 27. The eye surgery system according toclaim 20, wherein the microscopy optics comprise a camera to detect thelight-optical image of the eye fundus, and wherein the controller isfurther configured to control the camera to record the light-opticalimage and to control the visualization system to display arepresentation of the recorded light-optical image.
 28. The eye surgerysystem according to claim 27, wherein the controller is furtherconfigured to adjust the at least one property of the group ofproperties so that at least one condition of a second group ofconditions is fulfilled, the second group of conditions comprising: themagnification of the representation of the intraoperative OCT image andthe magnification of the representation of the preoperative OCT image beequal to a magnification of the representation of the light-opticalimage displayed by the visualization system; and the orientation of therepresentation of the intraoperative OCT image and the orientation ofthe representation of the preoperative OCT image be equal to anorientation of the representation of the light-optical image displayedby the visualization system.
 29. The eye surgery system according toclaim 27, wherein the controller is further configured to control thevisualization system so that the representation of the light-opticalimage and the representation of one of the preoperative OCT image andthe intraoperative OCT image are displayed simultaneously and areadjacent to each other.
 30. The eye surgery system according to claim29, wherein the representation of the light-optical image and therepresentation of one of the preoperative OCT image and theintraoperative OCT image are not overlapping each other.
 31. The eyesurgery system according to claim 29, wherein the representation of thelight-optical image and the representation of one of the preoperativeOCT image and the intraoperative OCT image are overlapping each other.32. The eye surgery system according to claim 27, wherein the controlleris further configured to control the visualization system so that therepresentation of the light-optical image and the representation of oneof the preoperative OCT image and the intraoperative OCT image aredisplayed consecutively.
 33. The eye surgery system according to claim32, wherein the representation of the light-optical image and therepresentation of one of the preoperative OCT image and theintraoperative OCT image are overlapping each other.
 34. The eye surgerysystem according to claim 20, wherein the controller is furtherconfigured to perform an image analysis of the preoperative OCT imageand an image analysis of the intraoperative OCT image, and wherein theadjusting of the at least one property is based on at least one of theseimage analyses.
 35. The eye surgery system according to claim 20,wherein the controller is further configured to detect at least oneoptical parameter of the optical system, and wherein the adjusting ofthe at least one property is based on the at least one opticalparameter.
 36. The eye surgery system according to claim 35, wherein theat least one optical parameter represents at least one focal length of agroup of focal lengths, the group of focal lengths comprising a focallength of an objective lens of the optical system and/or a focal lengthof an auxiliary lens of the optical system.
 37. The eye surgery systemaccording to claim 36, wherein the auxiliary lens is one of anophthalmoscopy magnifying lens and a contact glass.
 38. The eye surgerysystem according to claim 36, wherein plural auxiliary lenses havingdifferent focal lengths are provided, wherein each of the pluralauxiliary lenses may be selected to be disposed in a beam path of theoptical system.
 39. The eye surgery system according to claim 38,further comprising a user interface configured to receive data from auser, the data being suitable to identify the auxiliary lens disposed inthe beam path of the optical system.
 40. The eye surgery systemaccording to claim 38, wherein the controller is configured to identifythe auxiliary lens currently disposed in the beam path of the opticalsystem.
 41. The eye surgery system according to claim 40, wherein thecontroller is configured to identify the auxiliary lens disposed in thebeam path of the optical system by a measurement using the OCT device.42. The eye surgery system according to claim 40, wherein the controlleris configured to identify the auxiliary lens disposed in the beam pathof the optical system by analyzing the light-optical image.
 43. The eyesurgery system according to claim 40, wherein the plural auxiliarylenses have different identifiers of a group identifiers comprisingelectric and mechanical identifiers, and wherein a mount for theauxiliary lens disposed in the beam path is configured so that thecontroller can identify the identifier of the auxiliary lens disposed inthe beam path.
 44. The eye surgery system according to claim 20, furthercomprising a diagnostics system configured to record the preoperativeOCT image and to transmit the recorded preoperative OCT image to thedata interface of the controller.
 45. The eye surgery system accordingto claim 44, wherein the diagnostics system is configured to generatemark data representing a selectable location in the preoperative OCTimage, and wherein the controller is configured to receive the mark datavia the data interface and to control the visualization system todisplay a mark at a location in the representation of the intraoperativeOCT image, the location corresponding to the selected location in thepreoperative OCT image.